Engine.



AM 0 9 1 .l.. l v. A M D E T N E T A P SM vD R A W D E D. W A 6 0 D, 6 7 uI N ENGINE.

APPLIUATION FILED nu 21. 1903.

3 SHEETS-SHEET l.

N0 MODEL.

PATENTED MAY 17, 1904. W. DI EDWARDS.

ENGINE.

ArPLIoATIoN FILED un 21, moa.

N0 MODEL.

3 SHEETS-SHEET 2.

' No. 760,062. PATENTED MAY 1'7, 1904..

' W. D. EDWARDS.

ENGINE.

APPLICATION FILED MAY 21, 1903. N0 MODEL. l 3 SHEETS-SHEET 3.

A j ,2 (55 :-:V @l

www \\"J 4 I ,25 1f 22g 6a of my new engine.

UNITED STATES .fatented May 17, 1904.

PATENT OEEICE.

VILLIAM DfEDVARDS, OF BOSTON, MASSACHUSEITS.

ENGINE.

SPECIFICATION forming part 0f Letters Patent NO. 760,062, dated May 17, 1904.

Application filed May 2l, 1903. Serial No. 158,085. (No model.)

To all whom t may concern:

Be it known that I, WILLIAM D. EDWARDS,

of Boston, in the State of Massachusetts, haver ing on the piston before the spent steam es-4 capes through `the exhaust, as will now be more fully described by reference to the draw ings, in which- Figure l is an elevation, partly in section,

Fig. 2 is a horizontal central section of the cylinder of lthe engine shown in Fig. l. Figs. 3 and L are sections on lines 3 3 and t t of Fig. 2, on a reduced scale. Figs. 5 and 5 to 8 and 8, inclusive, are sectional diagrams, showing the different positions of the piston and of the distribution-valve dur` ing the operation.

Cylinder A has its heads a a formed with internal projections a2 a3, which, in connection with piston B, make high-pressur-e steamspaces B B2 and low-pressure steam-spaces B3 B4, so that the steam for running the engine flows first into space B', thereby forcing piston B in one direction, after which that supply of high-pressure steam expands out of space B and into space B4, the pressure of the low-pressure steam in space B4: forcing cylinder B in the opposite direction; but as will be clear the pressure of the low-pressure steam in space Bi cooperates with the pres* sure of a new supply of high-pressure steam admitted to space B2 to move piston B during one stroke, and the pressure of the high-pres sure steam in space B cooperates with the pressure of the low-pressure steam in space B3 to move piston B during the opposite stroke-that is, steam from the boiler is admitted to space B and steam from space B2 is admitted tospace B3 simultaneously to drive the engine one stroke, and from the boiler to space B2 and from space B to space Bi simulfor space B2, and these ports Z and d are controlled by valve D, whose through-ports Z2 and d serve to connect ports Z and d alternately with the steam-supply from valvechest F. These ports d and d serve alternately as inlet and outlet ports from spaces B and B2; but while either is serving as an outlet-port it opens only into port j of valve D. This portf has two branches, f f2, one, j", opening through port f3 into space B, the other, f2, through portf'L into space B4.

In the position of valve D (shown in Fig. 2) the exhaust-port f5 is shown open to port f4, while exhaust-portf' is closed lby valve D; but on shifting Valve D exhaust-portf will be open and f closed.

Valve D is shifted by pin G eccentric on crank-pin Gr and connecting-rod g, connected to valve-rod g', the pin G giving the necessary motion to valve D in addition to that which it has with piston B, for in this eX- ample of my invention valve D reciprocates with piston B and owing to the action of pin G is moved back and forth on piston B.

The supply-pipe H is provided with cutoff plate H', which lits over` valve D and covers through-ports Z2 Z3 except during thei time desired for admission of steam from the steam-supply, the amount of cut-off being easily determined by the width of plate H, as will be obvious from Fig. 2, while if plate H were omitted that function would be performed wholly by pin (-that is, throughports d2 Z3 are closed by plate H', as the width of plate H' determinesnand the relation of ports d2 and Z and Z3 d depend wholly on the relation of pin Gr with crank-pin G'- that is, the travel of piston B is determined by crank-pin Grt-and plate H' is stationary, except when moved for regulation, while IOO i'alve D is rcciprocated by pin G and piston B by crank-pin G, and therefore valve D, moved by pin G, will be moving inthe same direction as piston B, which is moved by crank-pin G', but at a slower rate, and this Will move ports Z and (Z2 out of register, thereby preventing further How of steam into space B at one stroke and move ports CZ and Z2 out of register, thus cutting off steam from space B2; but it will be seen that near the end of a stroke the motion of piston B will be opposed to the motion of valve D, and the result Will be the sudden opening of port Z of space B at the beginning of one stroke and of port CZ at the beginning of the opposite stroke.

The operation Will be plain from the preceding description, especially when taken in connection with Figs. 5, 5a to 8 and 8, inclusive, Which show the positions of the piston and its valve corresponding to the positions of the crank-pin G and the pin Gr eccentric thereon, these being represented as to their relative positions atG and Gr in the diagrams. Thus when the pins Gr and G have just passed their inner dead-center, corresponding to the positions shown in Fig. 5, steam is flowing into space B from the boiler and steam from space B2 is flowing into space B3, While spent steam from space B4 is escaping through the exhaust. points indicated in Fig. 6, steam from the boiler is cut off, but space B2 is still connected with space B3 and B2t with the exhaust. In Figs. 7 and 7*L the pins G and G are about to pass their outer ldead-center, and the steam in space B2 acts as a cushion While steam is about tov escape through the exhaust from spaceB3. In Figs. 8 and 8a the pins Gr and G have passed their outer dead-center and steam from the boiler is flowing freely into space B2 and steam from space B into space B2 while space B3 is open to the exhaust.v It Will be obvious that instead of steam other elastic iuids may be used and also that When external pressure is applied to reciprocate the piston the engine will be a compressor, air, for example, being first drawn through exhaust into spaces B3 and B2, and there corncompressed to one degree and then further compressed in spaces B B2, and thence dis- VVhen pins G G have reached the charged into a reservoir through H. The steam-channels /L 7L' and j j" about the outer and inner circumference of the ends of piston B aresupplied with steam from valve-chest F through small ports, as clearly shown in the drawings, and serve to permit a thin film of steam to travel in contact with the cylinder- Walls, raising the temperature of those Walls. While this is a desirable feature of my engine, I make no claim to it in this application, as it will form the subject of another application.

What I claim as my invention is` 1. The engine above described characterized by a piston with annular projections at each end and a cylinder With internal projections at each end tting Within the annular -ends of the piston and the annular ends of the piston fitting within the cylinder and over the internal projections of the cylinder; combined together and With valves and ports to provide high-pressure steam-spaces formed by the internal projections of the cylinder and the inner walls of the piston, and low-pressure steam-spaces formed by the inner Walls of the cylinder with its internal projections and the annular ends of the piston, all arranged and operating substantially as described.

2. In combination aV piston With annular projections at each end and provided With ports Z cZ; a cylinder with internal projections at each end, the internal projections of the cylinder tting within the annular ends of the piston, and the annular ends of the piston tting Within the cylinder and over its internal projections; and valves With through-ports Z2 Z3 controlling the ports Z CZ through the piston, all arranged and operating substantially as described.

3. In combination a piston With ports CZ Z through it; valves With through-ports Z2 Z3 controlling ports Z Z through the piston, and a cut-off plate H controlling' the` throughports Z2 d3, all arranged and operating substantially as described.

l WILLIAM D. EDWARDS. Iitnessesz G. A. ROCKWELL, C. B. MAYNADIER. 

